Carrier Localization Suppression by Multipath Transport in Helical Polyacetylene

The conduction sites in the main chain of helical polyacetylene (HPA) are arranged in a unique helical configuration, whereas conventional conductive polymers such as cis-polyacetylene and trans-polyacetylene have almost collinearly aligned conduction sites. Here we report the distinctive hole transport properties in HPA caused by the helical structure. Analyses of the hole diffusion with different models of the range of transfer integrals (TIs) reveal that the helical configuration produces multiple conduction paths in HPA. The holes propagate through multiple pathways, avoiding local paths with small TIs. This mechanism suppresses the localization of electronic states in HPA, which is inevitable in conventional one-dimensional conductive polymers.